Hey, question:

Here on campus have a high-speed internet connection that we all work off. And, us being poor college kids, most all of us have installed KaZaA or some other peer to peer file sharing agent, in order to get some free entertainment between classes.

Lately, however, the downloads from KaZaA as well as any other file sharing programs have slowed to an absolute crawl. We've gone from being able to download a song in 15 seconds to three days. The thing is, that it only affects peer to peer downloads. Downloading images or video from web pages remains as fast as ever. What makes it that much more puzzling is that uploads from our systems are still running at top speeds, upwards of 100 k/second. This happens regardless of what OS or file sharing agent you use. MSN instant messenger works just fine, except for the "send a file or photo" option, as the transfer never goes through.

The popular theory floating about campus is that the admins have installed some sort of selective firewall that blocks incoming transfers from such file sharing agents. When asked about it they deny it to the bitter end. And since there are only three of them I assume they would be able to keep a secret to themselves if they wanted. And I personally have never heard of such a thing. Although I admittedly have zero experience with large networks and how they operate.

My question is what is causing this lag in download times? If not a "selective firewall" then what?